Ball mill



June 14, 1932.V

BALL MILL Filed May 14, 1926 June 14, 193:?,u A F WENDLER 3,362,557

BALL MILL Filed May 14, 1926 2 Sheets-Sheet 2 Evy Patented June ld, 'i932 .UNETE STATES PATENT OFFQ ADOLPH F. W'ENDLEIQ, 0F BUFFALO, NEW YORK, ASSIGNOR T0 NATIONAL ANILINE 8o CHEMICAL CO. INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK BALL MILL This invention relates to improvements in reactors of the ball mi l type to adapt them for reactions in the nature of sulfur fusions.

Sulfur fusions are accompanied by excessive gas liberation in the early stages of the if: i,

reaction resulting in a violent ebullition or foaming of the ma ss; and in the latter stages by a viscos condition of the mass which finally hardens. Variations in temperature or local overheating during the fusion period have a decided effect on the final product, and consequently good agitation and avoidance of overheating is required at all stages to minimize foaming and to adequately control the product. For such reactions it is found that a ball mill, consisting of a heated rotating drum and loose agitating means, is peculiarly adapted, as the foaming condition in the early stages is reduced, due to the constant movement of the mass by the rotating drum and the pounding action of the balls, and the necessary temperature control in the latter stages is made possible by the uniform Working and spreading of the melt upon the drum Y by the agitating means. Additional advantages follovv from the adoption of the ball mill, for continued rotation of the drum after the melt becomes hard results in a breaking up and grinding of the product, and the subsequent solution is thereby greatly accelerated; furthermore the solution step can also be performed in the ball mill, thus avoiding the handling or transference of the melt until it is in the convenient liquid form for further treatment.

However, the evolution of gases and vapors necessitates a vent from the reaction zone comparatively free from a tendency to become clogged. Heating of the drum so as to produce even temperature conditions is also an imposed condition. Commercial operation presents further problems as to an economical yet certain drive, an adequate mounting of the rotating drum, and ready access F to the parts composing the structure.

Application led May 14, 1926. Serial No. 109,067.

This invention has for an object a ball mill construction adapted for reactions of the nature of sulfur fusions at any pressure. Another object is a ball mill having openings of a character that avoid clogging forl the escape of gases and vapors and for charging materials. Another object is a construction affording an evenly distributed heating or cooling of the mass under treatment. A further object is a drive insuring rotation of the drum at all times. A still further object is a drum With a mounting and associated inlet and outlet connections adapted for large scale or commercial operations. The invention also contemplates a construction readily erected, or taken apart, economical in operation, and capable of carrying out operations, such as grinding and mixing, in addition to those of fusing materials and spreading the resulting melt.

A. suitable construction embodying this invention comprises a rotating drum rotatably mounted Within a fixed housing. This enables the same heating conditions to be secured for all parts of the drum While avoiding the necessity of passing a heating medium through a rotating trunnion. It furthermore permits a rugged and simple driving means, comprising a pair of rotating shafts carrying rollers to engage the drum and to act as a support for the drum as Well, and a gear ring on the drum loosely engaging a pinion on a shaft supplement the friction drive in ease of momentary excessive eccentric loading. Within the housing are gas burners shielded to diffuse the hot products of combustion, and vents from the housing, provided With dampers, regulate the escape of hot gases. Axial openings in the ends of the drum are utilized for charging and gas escape, and these openings are constructed to avoid clogging. For cooling, a. fan is provided to bloiv air about the drum.

For a more complete understanding of the Cil invention reference is to be had to the accompanying drawings in which Fig. 1 is an elevation in section;

Fig. 2 is a vertical section on the line 2-2 et Fig. 1; and

Fig. 3 is a sectional view of a closure taken on line 8-8 of Fig. 1.

A sheet metal drum 10 with ends 11, 12 and cylindrical portion 13 is surrounded by cast iron rings 14, 15 one near each end. The rings ride upon cast iron' rollers 16, 17 and 18, 19 respectively, the rollers 16 and' 1S being mounted on a shaft 20, and the rollers 17 19 on a parallel shaft 21. The rollers 16, 17 are flanged to engage the ring 14 and restrain the drum from axial movement.V There is also secured to the drum a ring gear 22 which' is loosely engaged by a pinion 23 fixed to the shaft 20. Projecting axially from the end 11 is a frusto-conical charging opening 24 and riveted to the opposite end 12 is an axially alined outlet nozzle 25'. The nozzle has a flange 26 riveted to the drum end and the end 27 projects within the drum. The interior end of the opening through the nozzle is flared or tapered outwardly, as at 28. The agitating means' within the drum consists of a plurality of rows of balls 100 of east iron; these are preferably of a size and weight to project above a charge of reaction mixture in the drum and overcomel adhesion thereto at a low speed of rotation, e. g., 5 to 10 R. P. M.

A housing 30 encloses the drum. It consists of an inner steel shell 31 and an outer steel shell 32, each composed of sections bolted together, anda heat insulating packing 33 between them. This housing is readily erected or takenapart by removing the bolts holding sections together.

The parallel shafts 20, 21 project beyond each end of the housing where they are journaled in bearings 40, 41. A suitable reduc-L tion gearing 42v connects the shafts and a motor 43.

Vithin the housing and at a suitable distance below and extending' longitudinally of the drum are a plurality of gas burners each burner having a separate valve control. Above the burners arebaiiles or deflectors 51 to prevent direct impingement of the iame on the drum. Baiiles 52 are placed about the shafts which serve both to shield the shafts from the heat and to direct the hot gases about the drum. Vents 53 extend from the upper portion of the housing, and dempers 54 within the vents control the escape of gases. Extending into the housing at the middle portion is an air duc-t 55, with an upturned end 56 directed toward t-he drum, and a blower or fan 57 connected to its outer end. Thermometers 58, 59 extend within the heating space.

A pipe 60 is journaled in the outlet nozzle 25 and a gland 61 cooperates with the nozzle to form a stuiing box. A T casting 62 is secured to the pipe 60 and a vent pipe 63 extends upwardly from the T. A branch line 64 from the vent pipe conducts vapor to a reflux condenser 65, and a return line 66, with a trap 67 formed therein, carries condensate back to the outlet nozzle. Valves 68, 69 and 79 control the ilow of gases or vapors in the vent pipe and the branch line. The returned or reluxed condensate thus washes baci; into the drum solid depositions that may form in the nozzle. As an insurance against clogging ot the nozzle in ease ot ay sudden ebuilition filling the nozzle, a valve controlled pipe 71 extending from the T may be opened and a ram rod or the like inserted to push the material back into the drum; this operation can be carried on while the reaction is proceeding.

At the charging end there is provided a chute 8O with a removable section 81 that fits in the charging opening 24. The opening is provided with an explosion disk or flange 82 for sealing the opening when the chute section is removed. This flange comprises an iron ringl 83 with its opening closed by a thin sheet of metal 84; the metal sheet sufficiently thin so as to rupture when the maximum pressure desired in the drum is exceeded.

A manhole 90, formed in the charging end of the drum near its periphery, serves as a charging opening when in elevated position and a discharge opening for material or removal of the agitating means when in lowered position. I The manhole door` 91'` is carried by a screw 92 threaded in ae clamp 93, the clamp being hinged at 94 and secured at its free end by a shackle 95. A gasket 96 is inserted between the door and the manhole edge. To give access to the manhole two doors areprovided in thehousing end, one door 97 in alinement with the upper position of the manhole, and the other 98 in alineinent with the lower position. Tf the material to be removed from the tank is a liquid, the drum is brought to rest With the manhole 90 in its upper position, doors 97 and 91 are opened, a suction hose ispassed into thel drum and the liquid is sucked out. It' solid material or the agitating means is to ie removed, the drum is brought to rest with the manhole 90 in its lower position, the doors 9S and 91 are opened, and the material removed.

In carrying out sulfur fusions and the like in the above described apparatus, the drum 10 can be charged with the reacting 1nate rials either through the chute 81 or the manhole 90 and the charging openings sealed, whereupon the drum can be rotated and heated. An alternative method is to start the drum rotating and heat it to a desired temperature and then Charge the reacting material through the chute 81 over a period of time; when finally charged, the chute is removed and the receiving opening 24 is closed by the explosion flange 82. The mass is thereupon heated to atemperat-ure around 250O C., this depending on the materials under treatment and the product desired. The gases and vapors given off by the reaction mass escape through the outlet nozzle 27. As the drum rotates the contacting portions of the mass move With it, and other portions replace them, the extent of movement depending upon the rate of rotation, which is preferably about l R. P. M. The balls 100 also move with it until the force of gravity pulls them back to rotate over the freshly heated portion of the mass and release entrained gases. This action is repeated With all portions of the melt. If foaming should take place, the tapered or conical construction of the axial openings 24 and 27 returns any of the mass that may enter therein; and should any portions of the mass cling to the drum so as to fall into contact with the outlet nozzle 27, the projecting portion of the nozzle Within the drum serves as a shield to prevent entrance of the material into the pipe 60. As the reaction mass becomes viscous the balls knead it into contact With the shell of the drum forming a substantially uniform layer about it. Since the drum rotates Within the heat-ed zone, all parts of it receive the same amount of heat; consequently there is no local overheating due to unequal heat distribution. When the mass has been sufficiently baked in the drum, it is cooled by a blast of air from the blower 57 which sweeps about the drum to abstract heat therefrom; and the balls as they roll over the hardened melt, break it up and grind it. After cooling, caustic soda or sodium sulfide solution is added in suiiicient quantity for dissolving the melt. The drum is aga-in heated to facilitate the solvent action. Vapors that pass off are cooled in the condenser, and the condensate can be returned or reliuxed to the drum or thionator, in which case the condensate serves to Wash the outlet nozzle as Well as to maintain the desired dilution of the solution. `When complete, the solution may be removed by suction, as above described.

l claim:

l. A reactor comprising in combination a drum, means for rotating said drum, said drum having an axially alined opening, and a reflux condenser connected With said opening.

2. A reactor comprising in combination a rotatable drum, a housing enclosing said drum, an axially alined outlet nozzle extending through said housing and connected to said drum, a pipe journaled in said nozzle, a reiinx condenser connected to said pipe, and a vent pipe associated With said condenser.

3. A reactor comprising in combination a drum, means for supporting, means for rotating, and means for heating said drum, unattached free tumbling devices Within said drum for mixing and grinding material therein When the drum is rotated, said drum having axially alined openings at each end thereof, an explosion flange for closing one of said openings, a nozzlewithinthe other opening, a pipe journaled in said nozzle, and a reflux condenser connected to said pipe.

4. A reactor comprising in combination a drum, means for rotating said drum, a quantity of loose balls in said drum to mix and pulverize material Within the drum When the drum is rotated, said drum having an axially alined outlet opening therein, a reflux condenser connected to said opening, and a closure for said opening operable to permit a cleaning rod to be inserted into said opening during the rotation of said drum.

5. A reactor comprising in combination a rotatable drum, a housing enclosing said drum, heating means for said drum Within said housing, said drum having an axially alined opening in one end thereof, and a closure for said opening mounted on said end of said drum, said closure comprising an explosion flange.

G. A reactor comprising in combination a drum, means for rotating said drum, said drum having an axially alined inlet opening, a removable closure for said opening comprising an explosion flange, and a feed pipe adapted to be inserted in said opening.

7. A reactor comprising in combination a drum, means for heating said drum, means for rotating said drum, said drum having axially alined openings therein, an outlet nozzle in one of said openings, and a removable closure for another opening, said closure including an explosion disk.

8. A reactor comprising in combination a drum, means for supporting said drum, means for heating said drum, means for rotating said drum, unattached free tumbling elements Within said drum, said drum having axially alined openings therein, a reflux condenser attached to one of said openings, and feeding means associated With another of said openings.

9. A reactor comprising in combination a rotatable drum, means for rotating said drum, means for heating said drum, free tumbling elements Within said drum, said drum having axially aligned openings therein, a rotating pipe secured to said drum and extending through one of said axial openings into said drum, a fixed pipe connected to said rotating pipe, a vapor conduit connected to said fixed pipe, a condenser connected to said vapor conduit, and a conduit for returning condensate Y axially aligned o nings therein, a removable closure for one o said axial openings including an explosion disk, a rotating pipe secured to said drum and extendinginto said drum 5 through the other of said axial openings, a, fixed pipe connected to said rotating pipe, and means for condensing and refluxing vapors evolved in said drum, said means cornprising a vapor conduit connected to said l0 fixed pipe, a condenser connected to said vapor conduit, and a conduit for returning con* densa-te from said condenser to said fixed pipe. In testimony whereof I affix my signature.

a ADOLPH F, WENDLER. 1 

